Anti-uplift stability for CAES rock caverns in Hoek-Brown rock masses considering the location of crack initiation

The initiation and propagation of cracks induced by the high internal pressure affect the ultimate bearing capacity of underground rock caverns to a certain extent and then affect the uplift stability. Based on the limit analysis upper-bound theorem and the σ_n-τ_n-form Hoek-Brown (H-B) criterion, a limit analysis model for the uplift failure of circular rock caverns for compressed air energy storage (CAES) is established with the coupled mechanism of tensile crack initiation and shear-driven propagation, validated by numerical simulations and available analytical methods. When disturbance factor (D = 0), the positions of crack initiation are significantly influenced by the surrounding rock grade while being less affected by the cavern buried depth (H) and the rock’s uniaxial compressive strength (σ_c). The limit internal pressures in class-V to class-III surrounding rock masses are significantly influenced by H, while they are mainly affected by σ_c in class-II and class-I. When D ≠ 0, the positions of crack initiation in class-V to class-III are significantly affected by D, which is less influenced in class-II and class-I. The influence of rock disturbance on the limit internal pressure decreases with the increase in H and the grade of the surrounding rock masses, while increasing with the increase in σ_c. Diagnostic charts for the position of crack initiation and operating internal pressures are given. This study provides some new insights into the engineering design and assessment of operation risks for CAES underground rock caverns.